1. Field of the Invention
The present invention relates to a fluorescent lamp provided with increased luminosity achieved by applying a magnetic field to spread the arc throughout the enlarged volume of the lamp envelope.
2. Description of the Prior Art
The present invention is an advance over the initial description of the technique of arc spreading used in conjunction with fluorescent lamps in the co-pending applications Ser. Nos. 834,651 and 45,589, wherein arc spreading enable the fabrication of energy saving screw-in fluorescent lamps as replacements for incandescent lamps which are of inherently low efficacy in lumens per watt. Arc spreading lamps are not restricted to circular cross sections because the magnetic field of the arc spreading coil forces the arc to fill the entire volume of the lamp.
In October, 1976, Hasker described a new concept for fluorescent lamps in the Journal of the Illuminating Engineering Society wherein fine glass wool or quartz fibers were placed in the path of the arc discharge. The fibers provided a recombination structure for the ions and electrons increasing the voltage drop per unit length and increasing the lumen output per unit length enabling the construction of shorter lamps. The lamps described by Hasker are cylindrical with circular cross-sections bent into a U tube for a more compact assemblage.